• Nuclear Engineering and Technology
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• v.38 no.3
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• pp.277-284
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• 2006

In order to ensure the structural integrity of nuclear welded structures during design life, the fatigue life has to be evaluated by fatigue analysis procedures presented in technical codes such as ASME B&PV Code Section III. However, existing fatigue analysis procedures do not explicitly consider the presence of welded joints. A new fatigue analysis procedure based on a structural stress/fracture mechanics approach has been recently developed in order to reduce conservatism by erasing uncertainty in the analysis procedure. A recent review of fatigue crack growth data under various mean loading conditions using the structural stress/fracture mechanics approach, does not consider the mean loading effect, revealed some significant discrepancies in fatigue crack growth curves according to the mean loading conditions. In this paper, we propose the use of the stress intensity factor range ${\Delta}K$ characterized with loading ratio R effects in terms of the structural stress. We demonstrate the effectiveness in characterizing fatigue crack growth and S-N behavior using the well-known data. It was identified that the S-N data under high mean loading could be consolidated in a master S-N curve for welded joints.

• International Journal of Internet, Broadcasting and Communication
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• v.8 no.2
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• pp.23-30
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• 2016

In this paper, for the pratical building envoronments, the propagation properties of the electromagnetic waves of the sub-1GHz bands, including the 447MHz, 868MHz, and 715MHz, and the 2.4GHz band are experimentally observed in therms of the received signal strength indicator (RSSI) value. The compasion of the frequency bands can be utilized to efficiently construct the wireless sensor networks (WSN) for the building automation control. In order to measure the RSSI values in the building, an RSSI measurement system is first designed, in which the master part can transmit data packets and measure the corresponding RSSI values, and the slave part can respond the received data packets. Using the measurement system, the RSSI values are then experimentally measured at four types of building enviroments. From the experimental result analysis, we could notice that the sub-1GHz, especially the 447MHz band, showd a good communication performance for the building environment and could provide an efficient WSN construction when the data rate is relatively low.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.82-84
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• 2005

Fatigue assessment of welded structure is very sensitive to the method of local stress determination. Normally, hot spot stress which is surface stress extracted from 0.5t, 1.5t away from weld toe is widely used to obtain local stress. However, this method has a lot of limitation in the evaluation of fatigue strength. Therefore, mesh has to comply with strict requirements since stress extracted from this method strongly rely on mesh size and element types. And that method does not cover the stress gradient through thickness direction since only surface stress is considered. Recently, new method to obtain local stress is proposed, which is structural stress. This method has an advantage, which is mesh intransitiveness and covering the effect of both bending and axial stress in local area. In this paper, fatigue test data for various welded joints was analyzed to review the reliability of structural stress. As a result, it is verified that S-N curve using structural stress guaranteed single master curve for various joint type and testing condition.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.6
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• pp.151-158
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• 2015

This paper presents the real-time experiments of WA-DGNSS transmission system using a pseudolite and shows the performance of WA-DGNSS. We implement a server/client program to receive the WA-DGNSS data from the master station, and fabricate a pseudolite to transmit the WA-DGNSS data to users. The performance of the WA-DGNSS transmission system is tested by software and hardware GPS receivers, respectively. The experiments show that the WA-DGNSS data is well transmitted to GPS receivers without errors and thus WA-DGNSS works well.

• Journal of Korean Academy of Nursing
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• v.23 no.3
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• pp.356-368
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• 1993

The purpose of this study was to understand how patients experience their nurses, healing relation-ships. The 33 participants were patients who had been admitted to a general nursing unit of a university hospital in Seoul for more than one week, understood the study purpose and agreed take part, were fully conscious, able to communicate and over 20 years of age , their health was improving and they were ready for discharge. The data for this descriptive study using ground theory approach were collected by direct interviews with patients using five main questions derived from the literature and clinical experiences about their experiences of their nurses, healing relationships during hospitalization. Van Kaam’s method was used to analyse the data audio-recorded. Interpretation was enhanced consultations with two supervisors and one head nurse with a master’s degrees in nursing science, one nursing professor and one nursing docotoral candidate. Twenty - four patients said that they had formed a healing relationship with a nurse and nine said their relationship was not healing relationship. Six categories emerging from the characterizations of the healing relationships were valuable gratifying comforting trusting close and sympathetic. Descriptions of non - healing relationships were classified as none and poor. For this group of hospitalized patients nurses’ healing relationships were defined as valuable gratifying comforting trusting close as sym-Pathetic. Since the data suggest a change in the experiences during hospitalization, a gronded theory approach is recommended for further study.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.408-411
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• 2017

This paper deals with how to operate sensor data in smart livestock barn environment through EPCIS event schema design based on GS1 standard. We defines the types of sensors used in the smart livestock barn environment, describes the information using the GS1 standard identifier, standard event / master data structure, and standard interface for operating the sensor information, and stores / shares various sensor information of smart livestock barn defined in the schema structure.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.9
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• pp.3266-3285
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• 2014

With limited computing and storage resources, many network applications of encryption algorithms require low power devices and fast computing components. CHESS-64 is designed by employing simple key scheduling and Data-Dependent operations (DDO) as main cryptographic components. Hardware performance for Field Programmable Gate Arrays (FPGA) and for Application Specific Integrated Circuits (ASIC) proves that CHESS-64 is a very flexible and powerful new cipher. In this paper, the security of CHESS-64 block cipher under related-key differential cryptanalysis is studied. Based on the differential properties of DDOs, we construct two types of related-key differential characteristics with one-bit difference in the master key. To recover 74 bits key, two key recovery algorithms are proposed based on the two types of related-key differential characteristics, and the corresponding data complexity is about $2^{42.9}$ chosen-plaintexts, computing complexity is about $2^{42.9}$ CHESS-64 encryptions, storage complexity is about $2^{26.6}$ bits of storage resources. To break the cipher, an exhaustive attack is implemented to recover the rest 54 bits key. These works demonstrate an effective and general way to attack DDO-based ciphers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.284-287
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• 2000

Recently, developing medical devices have a tendency becoming the module for satisfying user's mutual complex needs. Because the most effective method for the observation of patients condition a diagnosis and a treatment is collecting data from various devices and controling operation following it. Module tendency is more popular due to manage easily totally many individual systems. This study implemented communication protocol to control by one control system connecting modular medical devices. Implemented system consist of one master module controlling all module and managing communication and many Slave modules. Communication between each modules introduced SPI(Serial Peripheral Interface) among many synchronous serial communication methods for the exact transmission and receipt of data. All communication executes by packet format. This can detect error. And, this protocol introduced PNP(Plug And Play) function that auto-detect connecting or removing module during running. This protocol exactly transmitted and received in faster speed more than 1Mbps. And in practical application to the ventilator this confirmed to give and take real-time data. And various functions by th central control system is implemented in this protocol.

• Survey Research
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• v.11 no.2
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• pp.161-176
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• 2010

The purpose of this study is to evaluate the opinion survey data quality used in theses and to suggest the data quality evaluation model. We used 16 items which were suggested by KASR(Korean Association for Survey Research) as a standard of survey data quality evaluation in thesis. According to the result, the data quality used in the theses is very poor level not to be accepted. And we tried difference tests between two proportions in order to find there were significant differences among stochastical variables. The result showed that there were some significant differences in sampling error and number of analyzing method between doctor and master. we suggested a model that was weighted by 9 special items for a survey data quality evaluation in a thesis by observing them from KASR's principles.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.5
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• pp.903-909
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• 2010

ADAS is the air defense control system performing air surveillance and identification of ROK and near air. This system is self-developed by Air Force, currently operated successfully as the alternative system of MCRC. ADAS processes converting and combining transferred the real time radar data detected by radars. additionally, it displays significant radar data as producing in tracks. Then, it uses the message queue for IPC(Inter Process Communication). the various tactical data processed in the server is ultimately send to the network management process through the message queue for transmitting to the weapon director console. the weapon director receives this transmitted tactical data through the console to execute air defense operations. However, there is a problem that data packet is delayed or lost since the weapon Director does not receive as the amount of tactical data from the server overflowed with air tracks and missions increased. This paper improved the algorism to display and transmit the various tactical data processed from ADAS server to numbers of the weapon director console in the real time without any delay or lost. Improved the algorism, established at exercise, the development server in the real operation network and the weapon director console, is proved by comparing the number of sending tactical data packets in the server and receiving packets in the weapon director.